The invention relates to a roll bar for vehicles, especially motor vehicles, consisting of segments mounted on opposite sides of the body, said segments having shaped sections mounted vertically and being connected together by at least one cross member.
A known roll bar of the species cited hereinabove (U.S. Pat. No. 3,656,803) is provided on an agricultural vehicle and comprises two vertical hollow members, said members having a box-shaped cross section. Each hollow member is wedge-shaped along its length and is formed by two parts which are U-shaped in cross section, said parts being connected by welding at their short legs. The disadvantage of this design is that the hollow members can scarcely meet the stricter safety requirements of today, even in agricultural vehicles. Moreover, the hollow members run parallel to one another in a direction which is transverse with respect to the vehicle, therefore, inboard of the wheels, sharply limiting the driver's space and his visibility. If the hollow members were to be moved above the wheel but given the same cross-sectional design, in order thus to provide more space, for example, for a closed cab, a number of deep-drawing tools, which would have a disadvantageous effect upon cost, would be required for this purpose.
In another known roll bar (French Pat. No. 1,539,482) for passenger cars, it is true that excellent results are achieved with regard to strength by using two shaped deep-drawn parts assembled to form a supporting brace. The different tools for the different shaped parts entail a high tool cost which is not justified for example, in the case of short vehicle-production runs.
Accordingly, an object of the invention is to provide a roll bar for vehicles which reliably withstands the stresses which may develop and whose components, especially the vertical segments, can easily be manufactured while providing complete freedom of design.
This object is achieved according to a preferred embodiment of the invention by virtue of the fact that each segment comprises two elements with the same profile which withstand deformations that increase the section modulus, said elements being formed by rolled sections assembled to form a hollow member and connected to one another by welding, gluing, or the like. It is advantageous in this regard for each segment, as viewed in cross section, to comprise two tubular structures, joined to a common rib. The structures are arranged symmetrically with respect to one lengthwise and one transverse plane of the segment. The cross-sectional shape of the structures is rectangular. However, it is also possible to make them round or oval. If the segments include deformations in a direction transverse to the vehicle, it is advantageous to shape the elements in separate manufacturing operations. The deformations are formed by construction lines and radii. The segments are joined by one upper and one lower cross member, whereby the upper cross member is constituted by a section, preferably a tube, whose cross section is such that it joins one of the opposite structures of the segments in each case. A system of corner plates is provided to connect a segment with the tube, said corner plates connecting the two structures with the tube. The corner plate system comprises a part which is bent at an angle and covers the segment and the tube areawise. In addition, the segments maintain a constant width throughout their length, whereby a covering is mounted on the outside, said covering beginning at the level of the belt rail and extending upward, said covering having a wedge-shaped pattern.
The principal advantages achieved by the invention include the fact that rolled sections are used for the elements of the segments, said sections being manufactured in the same set of rolls on a roll-section manufacturing tool. This saves considerable tool cost even when the segments must be deformed in the direction transverse to the vehicle in order to meet design requirements. Each element is processed separately. Shaping the structures increases the section modulus of the segments producing high rigidity in the segments and consequently in the roll bar. This is supported even further by the cross members which link the segments and by the corner plate system.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.